Carburetor for low grade hydrocarbons



I May 4, 1937.-

D. L. J. SMITH CARBURETOR FOR LOW GRADE HYDROCARBONS Filed Nov. 26, 193-4 4 Sheets-Sheet l 47' TOR/VLX y 1937- I D. L. J-. .,sM|T|-|- 2,079,363

CARBURETQ R FOR LOW GRADE HYDRQCARBONS Filed Nov. 26, 1934 v 4 Sheets-Sheet 2 [/VVE/V TOR. .DO/Y/MD 11.1]. 5M1 7%.

I T TOR/YEX May 4, 1937. D. L. J, SMITH 2,079,363-

CARBURETOR FOR LOW GRADE HYDROCARBONS Filed Nov. 26, 1934 4 Sheets-Sheet 3 l/vvz/vron. flomup [M]. 5m 11/.

May 4, 1937. D. J. SMITH CARBURETOR FOR LOW GRADE HYDROCARBONS Fild'Nov. 26, 1934 4 Sheets-Sheet 4 I 7' TOR/YE atente a? 1937 awn Donald L. J. Smith, Long Beach, Calif assignor to George ii". Smith, Long Beach, flalif.

Application November 26, 1934, Serial No. 754,789

11 Claims.

This invention relates to a carburetor for internal combustion engines whereby low gravity liquid hydrocarbons, such as kerosene, distillate or Diesel oil are supplied to the engine in a form usable by the average internal combustion engine.

An object of my invention is to provide a novel means of heating the mixing chamber of the carburetor, by a burner which is supplied with fuel from the float bowl of the carburetor.

Another object is to "provide a carburetor of the character stated, in which the heating chamber containing the burners, is open to the vacuum produced by the engine whereby at idling speeds, the engine will use a fixed gas produced from the burners and a slight additional amount of fuel from, the float bowl.

A feature of my invention resides in the manner in which the burners are arranged so that a flame will be produced by the burners at all engine speeds, regardless ofthe amount of vacuum in the manifold.

Another object of my invention is to provide a novel means of supplying air to the incoming fuel, said air being introduced between the float bowl and the mixing chamber of the carburetor. This air is preferably drawn from the main air intake of the carburetor so that a single air cleaner can be used.

Another object is to provide a carburetor of the character stated, which will start and subsequently operate the moto fuel. A feature of my invention resides in the novel method of attaching the float bowl to the mixing chamber of the carburetor whereby a vapor lock is eliminated, and which also permits the carburetor to be used either as the up-draft or downdraft type.

Another feature of my invention is that crankcase dilution is eliminated, due to thefact that v the engine idles on a fixed gas produced from the burners and upon small quantities of vapor and/or liquid drawn from the float bowl. At high speed, the temperature in the mixing chamber is suiflciently above the end point of the fuel to insure that no liquid fuel will enter the intake manifold. I

Other objects, advantages and features of invention may appear from the, accompanying drawings, the subjoinecl detailed description, and the appended claims.

In the drawings:

Figure l is a side elevation of my carburetor.

Figure 2 is a top plan View of the same.

upon the low gravity- Figure 3 is a view of the side of the carburetor opposite to that shown in Figure 1.

Figure 4 is a sectional view taken on lines 6-4 of Fig. 2.

Figure 5 is a fragmentary sectional view taken 5 on line 55 of Fig. 4.

Figure 6 is a fragmentary transverse sectional view of the outlet throat of the carburetor.

Figure '7 is a fragmentary plan view of the lower portion of the burner chamber.

Figure 8 is an enlarged sectional view taken on line 88 of Fig. 4.

Figure 9 is an enlarged sectional view taken online 9-9 of Fig. 2. v

Figure 10 is an enlarged sectional view taken on 15 line ill-4U of Fig. 1.

Figure 11 is a fragmentary horizontal sectional view thru the idling ducts of the mixing chamber.

Figure 12 is a side elevation of my carburetor with parts broken away to show interior construction.

Figure 13 is a horizontal sectional view similar to Fig. 8, and illustrating a modified form of idling jet.

Figure 14 is a buretor.

Referring more particularly to the drawings, my carburetor comprises a float bowl i and a mixing chamber 2. The float bowl i comprises the usual float chamber 3 into which the liquid hy- 3o drocarbon is forced. Fuel enters the chamber 3 thru a pipe 4, and the usual float controlled valve (not shown) controls the flow fuel from this pipe.

The mixing chamber 2 is provided with a nipple 5 which has exterior threads. The float bowl screws onto this nipple. Thus, it will be evident that the float bowl can be arranged in any position so that the carburetor canbe used either as an up-draft or a down-draft.

A bore 5 is provided in the body of the float bowl 40 l, and the opening at the bottom of this bore is controlled by a needle valve 1. Thus, the amount of fuel moving to the mixing chamber of the carburetor is controlled.

A port 8 connects the bore 5 and the outlet throat 9, of the float bowl. A hood it is provided on top of the float bowl i for the purpose of conducting air to the incoming fuel. An air vent it! connects the hood ill and the float chamber 3. An opening 52 also connects the hood H! and 4 the outlet throat 9, to admit air to the fuel, thereby decreasing drag. A pipe 03 extends from the hood iii to the sump i l, of the mixing chamber. Thus, it will be evident that the flow of air is diagrammatic view of my carsupplied thru the pipe 58 to the hood it, and 55 thence thru the opening l2 to the fuel. The fuel and air pass into the nipple 5 and thence into a passage IS, in the mixing chamber. After the engine has stopped, the heat from the mixing chamber will vaporize the fuel in the float bowl and these vapors will rise into the hood l0, thence downwardly thru the pipe l3 and will be-deposited in the sump l4. The fuel in the sump is used for starting or is gradually used by the burners, as will be further described.

A vertical wall iii in the passage I5 causes the fuel to take a tortuous passage. The fuel then passes over the top of the wall, thence downwardly, and finally thru a pair of holes l1-l1 which holes connect the passage l5 and the venturi i8. The holes l1 are placed slightly above the lower wall of the passage I5 so that any unvaporized heavy ends of the fuel will settle at the bottom of the passage, and only the vapors will pass into the venturi [8. The unvaporized heavy ends, while resting on the bottom of the passage I5, will be heated and. vaporized, as will be evident from the subsequent description.

The venturi i8 is of the duplex type, consisting of an upper sleeve i9 and a lower ring 20. The ring 20 is slightly spaced from the sleeve I9 so as to provide an annular passage 2| thru which the vapors pass from the holes H1. The venturi is positioned in the central mixing bore 22, of the carburetor, and the usual throttle valve 23 is provided immediately above the top of the sleeve I9.

A heating chamber 24 surrounds the central bore 22 and the intake passage l5. The heating chamber 25 is arranged in the sump i4 of the carburetor, and includes a transverse wall 26 positioned above the floor of the sump. A plurality of burners 21 are mounted in the wall 26 and each burner is open at the bottom to the sump l4. A Venturi ejector 28 is provided in each of the burners. A horizontal bore 29 extends thru the wall 26 and each of the burners is formed with a plurality of holes 30 which open into this bore. Fuel is conducted to the bore 29 thru the pipe 3| which extends from the float bowl I. 32 at one end and into the fitting 33 at the other end.

Fuel passes thru a duct 34 in the bowl casting, thence past a needle valve 35 and then into the fitting 33. The needle valve 35 thus adjusts or regulates the amount of fuel supplied to the burners 21.

A spark plug 36 extends into the heating chamber 25, and a coil (not shown) furnishes a continuous spark to this plug. Thus, if the flame from the burners 21 should be extinguished, the spark plug will immediately light these burners.

As previously stated, the pipe l3 conducts vapors and liquid from the float bowl I to the sump l4. The liquid will be deposited in the sump; and for startin: purposes, I provide an electric element 31, of usual and well known design. An extension tube 38 of the element 31 extends thru the wall 26 and conducts the vapors to a point adjacent the top of the burners 21. If the liquid in the sump l4 should be high enough to close the bottom of the burners 21, vaporization of this liquid would not cause it to pass into the heating chamber 25 unless a conduit 38, or the like, were provided.

The element 31 is used when starting a cold engine and suflicient fuel can be drawn into the sump I4 by flooding the carburetor. A transverse wall 39 confines the lize of the heatlni The pipe 3| screws into the coupling.

chamber 25. A plurality of holes 40 in the wall 39 permit the gases and the heat from the burners 21 to pass into the hot air chamber 24. A flow of air must be induced thru the burners 21, and for this purpose, I provide a plurality of air ports 4| which extend thru the wall of theheating chamber 25 and open into the air intake 42 of the carburetor. The ports 4| are preferably immediately below the lower edge of the Venturi ring 20. It is found that the rapid flow of air thru the carburetor will induce an upward flow of air thru the burners 21 which will draw'the fuel intothe burners for the purpose of burning the same within the heating chamber. If desired, a thermostat 43 can be attached to the mixing chamber of the carburetor, and coupled thru links 44 to the choke valve '45, for an automatic choke to be used for initial starting. At idling speeds of the motor, it might be found that the burners 21 would not draw the fuel to the top of said burners, in which case, a flame can be caused to burn at small orifices 46 which are drilled thru the top of the wall 26 into the bore 29. The flame in these orifices will be small, but sufiicient for idling purposes.

When idling, the engine utilizes a fixed gas from the burners 21 and 46, and this gas is admitted to the manifold of the engine thru a plurality of ports 41 in a ring 48 pressed into the central borev 22 of the carburetor.

The ports 41 extend into the heating chamber 24. The fixed gases might be too lean 'for the motor at idling speeds and it is therefore necessary to add asmall amount of idling fuel. This idling fuel is supplied thru a fine, drilled hole 49, which extends from adjacent the needle valve 35, to a fitting 50 on the top of the float bowl I. A small amount of air is also drawn into the fitting 50 thru a hole 5| which connects with the hood in. The pipe 52 screws into the fitting 50 and the other end of this pipe screws into the idling passage 53 in the mixing chamber of the carburetor. v

The idling passage 53 extends thru the body of the mixing chamber to a vertical tube 54. This tube terminates adjacent the ring 48 and one of the ports 41 extends to the tube whereby the vapors emitted from the tube are introduced into the intake manifold. A needle valve 55 controls the flow of vapors thru the idling passage 53.

If desired, the pipe 52 can be eliminated, and idling vapors can be introduced'into the hot air chamber 24 thru the holes 56-51, as shown in Fig. 13. The hole 55 extends into the fuel intake passage I5, and the needle valve 58 controls the amount of idling fuel to be admitted into the hot air chamber 24. As shown in Fig. 13, the gases in the hot air chamber are enriched an amount sufficient to permit the motor to idle. The gas and vapor pass into the intake manifold thru the ports in the ring 48 in the same manner, as previously described.

'Additional air for idling purposes is conducted thru the pipe 59 which is open to a port 60 ex'- tending into the air intake of the carburetor. The upper end of the pipe 59 is open to one of the ports 41 in the ring 48.

In operation, when starting cold, the heating element 31 is started, and the liquid fuel in the sump i4 is vaporized. As soon as the vapors form, the spark plug 36 ignites them and hot gases circulate around the fuel passage l5 and the central bore 22. As soon as these passages are thorough y heated. or as soon as the burners are ignited, the motor can be started. Liquid fuel is drawn out of the float bowl I past the needle valve i into the passage 95, thence thru ,the port I? thru the Venturi i8 and thence into the intake manifold of the engine. As previously stated, the burners 21 will continue to burn and will provide the necessary amount of heat at all speeds of the engine. A't idling speeds, the fixed gas from the burners will supply part of the fuel and an additional amount will. be supplied from the float bowl I thru the pipe 52, the passage 53 and the pipe 56.

A sump drain 6! is provided in the bottom of the sump it for the purpose of preventing too great an accumulation of liquid in the sump.

That is, the liquid level must not reach the bottom of the burners 21 or air would be shut off from them.

A spark plug 62 may extend thru the body of the mixing chamber 2 into the fuel passage Q5. The purpose of this spark plug is to further break down the low gravity fuel into a product which is advantageous in the operation of the engine.

Having described my invention, I claim:

1. A carburetor including a mixing chamber, a float bowl attached to the mixing chamber, a sump in the mixing chamber, a heating chamber in the mixing chamber, burners in the heating chamber, a heating jacket surrounding the mixing chamber, said heating jacketbeing open to the heating chamber, and a conduit extending from the bowl to the sump whereby fuel vapors are collected from the bowl and deposited in said sump, or air is admitted to the bowl from the mixing chamber.

2. A carburetor comprising a mixing chamber. a float bowl attached to the mixing chamber, a heating chamber in the mixing chamber, burners in the heating chamber, a heating jacket surrounding the mixing chamber, said heating jacket being open to the heating chamber, a fuel conduit extending from the bowl to the burners, a sump in the bottom of the mixing chamber, and a vapor conduit extending from the bowl to the sump whereby vapors are collected from the bowl and deposited in the sump, or air is admitted to the bowl from the mixing chamber.

3. A carburetor including a mixing chamber, a float bowl attached to the mixing chamber; a sump in the mixing chamber, a heating chamber in the mixing chamber, burners in the heating chamber, a heating jacket surrounding the mixing chamber, said heating jacket being open to the heating chamber, a conduit extending from the bowl to the sump whereby fuel vapors are collected from the bowl and deposited in said sump, or air is admitted to the bowl from the mixing chamber, and a heating element in the'sump whereby fuel deposited in the sump is vaporized.

4. A carburetor comprising a mixing chamber,

having a central mixing passage and an air intake, a sump in the bottom of the mixing chamher, a float bowl attached to the mixing chamber, a vapor conduit extending from the top of the float bowl to the sump whereby the vapors are collected in the sump, or air is admitted to the bowl from the mixing chamber, a heating thru the burners, and fuel intake means extending from the bowl to the mixing passage.

5. A carburetor comprising a mixing chamber having a central mixing passage and an air intake, a sump in the bottom of the mixing chamber, a float bowl attached to the mixing chamber, a vapor conduit extending from the top of the float'bowl to the sump whereby the vapors are collected in the sump or air is admitted to the bowl from the mixing chamber, a heating chamber in the mixing chamber, burners in the heating chamber, a fuel conduit extending from the float bowl to the burners, a heating jacket surrounding the mixing chamber, said heating jacket being open to the heating chamber, said heating chamber having ports therein which open into the air intake whereby air is drawn thru the burners, .a Venturi ejector in the central mixing passage and fuel intake means extending from the float bowl to the Venturi ejector.

6. A carburetor comprising a mixing chamber having a central mixing passage and an air intake, a sump in the bottom of the mixing chamber, a float bowl attached to the mixing chamber, an air conduit extending from the top of the float bowl to the sump, a heating chamber above the sump, burners mounted in the floor of the heating chamber, said burners being open to the sump whereby air is admitted into the burners. a fuel conduit extending from the bowl to the burners, a heating jacket surrounding the mixing chamber, said heating jacket being open to the heating chamber, a Venturi ejector in the central mixing passage, and fuel conduit means extending from the float bowl to the ejector.

7. A carburetor including a mixing chamber, a float bowl attached to the mixing chamber, a sump in the mixing chamber, a fuel heating chamber in the mixing chamber, burners under the fuel heating chamber, a heating jacket surrounding the mixing chamber, said heating jacket being open to the hot gases from said burners, and a conduit extending from the bowl to the sump whereby fuel vapors are collected from the bowl and deposited in said sump or air is admitted to the bowl from the mixing chamber.

8. A carburetor including a mixing chamber, a float bowl attached to the mixing chamber, a sump in the mixing chamber, a fuel heating chamber in the mixing chamber, burners under the fuel heating chamber, a heating jacket surrounding the mixing chamber, said heating jacket being open to the hot gases from said burners, a conduit extending from the bowl to the sump whereby fuel vapors are collected from the bowl and deposited in said sump or air is admitted to the bowl from the mixing chamber, a fuel conduit extending from said bowl to the burners, and the air intake of said burners being open to the sump.

9. A carburetor comprising a mixing chamber, having a central mixing passage and an air intake, a sump in the bottom of the mixing chamber, a float bowl attached to the mixing chamber, a vapor conduit extending from the top of the float bowl to the sump whereby the vapors are collected in the sump, or air is admitted to the bowl from the mixing chamber, a fuel heating chamber in the mixing chamber, burners under the fuel heating chamber, a fuel conduit extending from the float bowl to the burners, a heating jacket surrounding the mixing chamber, said heating jacket being open to the hot gases from saidburners, said heating jacket having ports of the float bowl to the sump whereby the vapors are collected in the sump, or air is admitted to the bowl from the mixing chamber, afuel heating chamber in the mixing chamber, burners under the fuel heating. chamber, a fuel conduit extending from the float bowl to the burners, a heating jacket surrounding the mixing chamber, said. heating jacket being open to the hot gases from said burners, said heating jacket having ports therein which open into the air intake whereby air is drawn thru the burners,

fuel intake means extending from the bowl to the mixing chamber, the air intake of the burners being, open to the sump.

11. A carburetor comprising a mixing chamber having a central mixing passage and an air intake, a sump in the bottom of the mixin chamber, a float bowl attached to the mixing chamber, an air conduit extending from the top of the float bowl to the sump, burners mounted below the fuel heating chamber said burners being open to the sump whereby air is admitted into the burners, a fuel heating chamber above the sump, a fuel conduit extending from the bowl to the burners, a heating jacket surrounding the mixing chamber, said heating jacket being open to the hot gases from said burners,

and also having ports therein which open into the air intake passage whereby air is drawn thru the burners, a Venturi ejector in the central mixing passage, and iuel conduit means extending from the float bowl to the ejector.

DONALD L. J. SMITH. 

